Raver32 writes "Mars will be transformed into a shirt-sleeve, habitable world for humanity before century's end, made livable by thawing out the coldish climes of the red planet and altering its now carbon dioxide-rich atmosphere.
How best to carry out a fast-paced, decade by decade planetary face lift of Mars — a technique called "terraforming" — has been outlined by Lowell Wood, a noted physicist and recent retiree of the Lawrence Livermore National Laboratory and a long-time Visiting Fellow of the Hoover Institution.
Lowell presented his eye-opening Mars manifesto at Flight School, held here June 20-22 at the Aspen Institute, laying out a scientific plan to "experiment on a planet we're not living on.""

Yeah, why wait until we've actually surveyed it for an existing ecosystem or other signs of life, when we can ensure there is life on Mars, if that's all we care about?

I mean, what value could learning about extraterrestrial life have, when it's at the closest planet for several light years likely to have some similar to ours? We'll study the next one, even though that means interstellar travel.

We've proven how carefully we protect environments when we don't understand them, right here on Earth, right?

"differently" from what? I mean, are you supposing that one cannot hold a positive opinion of the movie after having read the original story? Are you just venting the classic Philip K. Dick pet peeve, that all the movie adaptations butcher the story and miss the point? (If nothing else I enjoyed that the film kept the question of whether "Quaid's" adventure was real or not totally ambiguous...) Or are you just being a title snob? (*ehem* It's called Do Androids Dream of Electric Sheep? thank-you-very-much...)

If the whole point of bringing up "Total Recall" here is just to joke about Martian Terraforming, then might not the movie be a better fit anyway?

We Can Remember it for You Wholesale was the basis for Total Recall, and Do Androids Dream of Electric Sheep was the basis for Bladerunner. Not to enter the debate about whether the movies should have followed the original Philip K. Dick, but you at least have to know the relationships.

I was not confusing Total Recall and Bladerunner (to use the rather less elaborate titles...) I was just providing another example of Title Bitching. I could as easily have said "Excuse me, sir, but the proper title is Macross" or "I can see by your use of the title Godzilla that you are not familiar with the original film..." Just imagine it in a Simpsons "Comic Book Guy" voice - it could be about just about anything steeped in nerd-contention.

Problem with KSR's plan is that it involves rerouting comets and sending them through Mars' atmosphere. Basically the whole thing is based on technologies that don't yet exist. Great books (I own/read them all) but not that practical in the short time scale. I like the soletta mirror a lot, though, I think that was the best thing in there (short of the space elevator, whose relevance is widely known already.)

Jeepers, what is this foreign concept called "terraforming [wikipedia.org]" [that's been discussed for at least 50 years] - I'll try looking for information on this new resource called the Inter-Net and report my findings as soon as possible.

Jeepers, what is this foreign concept called "terraforming [wikipedia.org]" [that's been discussed for at least 50 years] - I'll try looking for information on this new resource called the Inter-Net and report my findings as soon as possible.

Wish me luck.

Step away from the computer, Mr. President. Here, I have a nice shiny thing for you.

I always wondered if terraforming could just be done my massive planting of hardy fauna. A ton of trees (like a rainforest), should drastically change even weather patterns...I always thought that it would be an interesting experiment for a lander to plant - and tend - some cacti or something and see what would happen over time.

I do think that the time span is a bit idealistic, and doesn't account for the Law of Unintended Consequences, but the idea is sound.

depends on the planet.If the planet has little/no water or 'stuff-that-can-be-made-to-water', and/or little or little/no oxygen that can be put into the atmosphere (with respect to the size of the planet, not an absolute "little" here), then it'll take more than just tossing some hearty growing things on the planet.

As for 100 years, it depends on what they plant, but that seems fairly reasonable, if they can find something both (a) hearty enough, and (b) fast growing enough. I saw a project reling on Kudzu,

If the planet has little/no water or 'stuff-that-can-be-made-to-water', and/or little or little/no oxygen that can be put into the atmosphere (with respect to the size of the planet, not an absolute "little" here), then it'll take more than just tossing some hearty growing things on the planet.

Maybe if they're lucky, they'll find a nuclear reactor left behind by an ancient alien civilization that would melt the vast quantities of ice hidden beneath Mars's surface, thereby giving the red planet an almost instantaneous atmosphere!

Whether or not you can change the CO2 for oxygen is irrelevant if you can't magic up a lot of nitrogen. And remember you're talking about replacing most of a planet's atmosphere with a different element altogether. Its not feasible on a century scale.

So what do you do with it? 95% CO2 on mars, you could put some plants there (they don't seem to need the nitrogen, at least for photosynthesis). But that will only get you the O2 and create a sink for water (whi

I always wondered if terraforming could just be done my massive planting of hardy fauna. A ton of trees (like a rainforest), should drastically change even weather patterns...I always thought that it would be an interesting experiment for a lander to plant - and tend - some cacti or something and see what would happen over time.

The problem is you need to raise the temperature of the atmosphere in order for most anything to grow, because there's no precipitation. The cycle can't begin until you've done that first step.

I haven't RTFA, but there was a show on Discovery Channel a while back where one of the guys who had designed a series of Mars missions for Lockheed/NASA back in the 80's (and he's still fighting for them) had proposed actually building a bunch of factories on Mars whose sole output would be greenhouse gases. Their entire purpose would be to just pump billions of tons of what we'd call pollutants on Earth into the Martian atmosphere. Supposedly you could raise the planet's temperature by 10 degrees over 100 years using this method, which would be enough to start releasing the water trapped in the ground as ice into the atmosphere, creating clouds and precipitation for plants. Then you could start planting forests, which would thrive in the CO2-rich Martian atmosphere and would begin to create the oxygen we need to breathe.

Humans could live on Mars as the terraforming process was ongoing, but they would need to be in enclosed colonies until the process was complete. Eventually, though, they'd be able to venture out into an Earth-like world.

I'm curious to see how the author of this article thinks the process could be sped up - the Discovery show said it would take thousands of years given current technology before the air would be both warm enough to live in and breathable for humans.

Factories on earth emit "greenhouse gasses" i.e. CO2, because they can easily import carbon-containing fuels and oxygen from the atmosphere, and burn them to provide energy and CO2. Since the fuel and the oxygen would need to be imported from off-planet, why bother with the factory? Just import CO2, perhaps from comets (dry ice?)...

First, the dry ice comments are out past saturn. But if you are going out there, then skip the CO2. Instead, go to ammonia. It is FAR better of a greenhouse gas. In addition, it breaks down to N2; simple nitrogen gas which is our buffer gas. In addition, is is through that the majority of ammonia asteroids contain a fair amount of water. The last thing Mars needs is more CO2.

I haven't RTFA, but there was a show on Discovery Channel a while back where one of the guys who had designed a series of Mars missions for Lockheed/NASA back in the 80's (and he's still fighting for them) had proposed actually building a bunch of factories on Mars whose sole output would be greenhouse gases. Their entire purpose would be to just pump billions of tons of what we'd call pollutants on Earth into the Martian atmosphere. Supposedly you could raise the planet's temperature by 10 degrees over 100 years using this method, which would be enough to start releasing the water trapped in the ground as ice into the atmosphere, creating clouds and precipitation for plants. Then you could start planting forests, which would thrive in the CO2-rich Martian atmosphere and would begin to create the oxygen we need to breathe.

Humans could live on Mars as the terraforming process was ongoing, but they would need to be in enclosed colonies until the process was complete. Eventually, though, they'd be able to venture out into an Earth-like world.

I'm curious to see how the author of this article thinks the process could be sped up - the Discovery show said it would take thousands of years given current technology before the air would be both warm enough to live in and breathable for humans.

Ever read the Mars trilogy [wikipedia.org] by Kim Stanley Robinson (Red Mars, Green Mars, Blue Mars)?
One of its central themes is the terraforming of Mars, and specifically includes the use of greenhouse gas factories, along with bio-engineering of plants and algea to seed the soil, with human colonists living there during the process. Quite the good read if you are into sci-fi, though it starts a bit stronger than it ends.

You really just don't get how hostile Mars actually is. On average, at the summit of Mt. Everest, air pressure is several hundred times what it is on Mars, and it's 60F warmer than on Mars, and nothing grows there. Antarctica is even balmier than Mt. Everest, and still nothing significant grows there. And those places at least have plenty of clean water.

I always wondered if terraforming could just be done my massive planting of hardy fauna.

And I often wonder why I can't just take any type of plant and stick in some styrofoam in the closet and wait for it to turn the closet into a lush arboretum. Yet everytime I try this, everything just ends up dead...

I'm only a lay-man, and I only know what I read in textbooks. If any of this is wrong, please correct me.

Some problems with this whole scheme.

1) Rich in carbon-dioxide, but only relatively. The atmosphere is so thin that even if the CO2 were converted to a more human-friendly mix, it's still too thin, and too cold.2) The atmosphere can't be enriched with more material because Mars can't hold it. Too gravity, and not a strong enough magnetosphere (which is how Venus holds it atmosphere).3) No internal dynamo. Mars has a cold core, leading the aforementioned problems.

The near vacuum surface pressure combined with intense cold will kill cactus. Cactus lives in the desert. What you need to plant is something green that grows well in Antarctica. So go look at pictures of Antarctica, and pick your favorite plant from there.

Mars will be transformed into a shirt-sleeve, habitable world for humanity before century's end, made livable by thawing out the coldish climes of the red planet and altering its now carbon dioxide-rich atmosphere.

Mars doesn't have a carbon dioxide-rich atmosphere. Mars doesn't have an anything-rich atmosphere. Yes, what atmosphere Mars has is mostly CO2, but what atmosphere Mars has is actually a pretty decent approximation of vacuum; the thickest parts of it are barely 1% of typical atmospheric pressure on earth.

The whole article doesn't actually include any specifics, it's just handwaving of the "and then a miracle occurs" sort:

Overall, Wood said that a workable plan can be scripted to raise the average temperature of Mars, rid the world of excess carbon dioxide, as well as generate soil to support agriculture.

Right. We'll get right on that. We only have 93 years to go, according to this article.

Indeed. No specifics whatsoever. I mean, the scale of this is mind boggling. Consider the Earth's atmosphere is about 78% nitrogen, providing much of the mass that gives us comfortable pressures. What gas will fill this role on Mars? Also, where is all the water going to come from? There is a lot of evidence of lots of water having flowed on Mars in the past, but that was billions of years ago. And finally, where is the oxygen going to come from? How can you liberate all that breathable oxygen from the iron

Yes, what atmosphere Mars has is mostly CO2, but what atmosphere Mars has is actually a pretty decent approximation of vacuum; the thickest parts of it are barely 1% of typical atmospheric pressure on earth.

I've often wondered about this. If you did manage to create an atmosphere on Mars, would there be sufficient gravity there to keep it in place, or would it simply drift off into space?

What does that mean? Mars doesn't have enough gravity to hold enough gas at its current temperature. If we warm it up, that problem increases. You can't just wish that problem away. Mars doesn't need heat or oxygen to be Earth-like. Mars needs mass.

If Mars doesn't have the gravity to hold a viable atmosphere, then we'll have to build enclosures that contain their own atmosphere. If we're doing that, then there's no real difference between colonizing Mars vs colonizing the moon.

The point behind Biosphere was to create a naturally self-sustaining system, so they weren't supposed to use CO2 scrubbers or any such similar technology. Additionally, it was determined that the concrete foundations were binding CO2 as they cured (concrete cures for years and years), causing still more problems.

Blah blah blah. It was a total screwup, not just in management, but in pure conception. They needed to start with a working system and then figure out how to make it self sufficient, instead of starting with a system that they thought would work, and trying to live in it indefinitely. Does anyone really think we'd start off with a system that needed no outside inputs? It's not realistic. Basically the only thing they proved is that they didn't do very well at making a self-sustaining system.

Actually, only partially correct. Yes, the solar wind will strip away the atmosphere, but it happens slowly. Over millions of years. If we develop the technology to introduce the atmosphere in the first place, we'll have no difficulty keeping it topped up.

My understanding is most of these proposals include the idea of continuously replacing atmosphere.The geological scales over which Mars would lose its atmosphere are not that important to humans anyway.So, wouldn't make Mars a natural planet.

I have similar thoughts as well, but having gone over the scenarios a few times Venus has a LOT of problems that would be nearly impossible to overcome. Venus seems to have a problem that carbon was never sequestered into solids on the surface. In fact it looks like Venus, Earth, and Mars all started in very similar states, and that by simply being closer to the sun, Venus ended up with significantly more CO2 in it's atmosphere which lead to the runaway greenhouse effect. So unless we manually remove the CO2 (huge undertaking especially considering the atmospheric pressure of Venus) that's not going to change.

The other major problem is that the rotation of Venus is extremely slow, thus leading to virtually no magnetic field. This means that it would be bombarded by extreme amounts of solar radiation on its surface if the atmosphere were cleared.

I read an interesting book on terraforming the solar system, and the author purposed that we could crash a comet (or few) into Venus to supply water, help cool the planet, and jump start its rotation. Of course needless to say I'm not exactly sold on playing intergalactic pool with planets in our solar system:)

Venus has a thick crust and no plate techtonics, so there's no way for carbon dioxide emitted by volcanoes to be recycled into the interior; it just builds up. Earth was lucky enough to have most of its crust stripped away four billion years ago in the collision that formed the moon.

This is an interesting question for property rights theorists. Many people adhere to some sort of Lockean view that by modifying this untouched land, the terraforming organization then owns all of Mars. But then some would say it's a sort of "common heritage" that can't be so privatized. It's also extremely difficult to just terraform "one part" of Mars. (Imagine keeping one part at 1 atm and the rest at Mars's regular atmospheric pressure.)

Regardless, anyone who goes through the expense of terraforming Mars, even a government, is going to want some assurance that the rest of humanity won't leech off their work.

trace the evolution of the hudson bay company [wikipedia.org] into modern canada: i don't see the mass of canadian citizens as serfs of a corporation. the colonizaiton of mars under corporate provenance would probably have a similar uncontroversial and mundane development arc. in fact, any such corporate colonization of mars under government oversight would probably consult a historical study of the hudson bay company directly as a model for potential pitfalls to avoid

i'm sorry, but in reailty, the balance between individual rights and corporate provenance isn't so difficult or immobile. there is no massive conflicts, and the hudson bay company still exists today: what was once the corporate master of much of north america is now simply a department store [hbc.com]. but of course, you read most science fiction, or talk to a paranoid schizophrenic, or even consult certain lowest common denominator youth subcultures, and you get the impression that corporations are these unstoppable sociopathic vampires out to turn you into an unthinking slave. hardly. reality is just not that interesting, sorry

Yeah, well. Then the Dutch East India company obviously did a much better job controlling their colony in South Africa than Hudson Bay did in Canada. The solution in South Africa was to abandon the colony and take your chances on the frontier. Probably a little harder to independently live off the land on Mars though.

As with anything else, property rights on Mars will go to those with the ability to enforce them. International "nobody owns this place" treaties like those governing Antarctica and the Moon are only useful as long as those places have nothing of value. In the end, if a region is worth occupying, only those with the weapons needed to keep others out will really "own" the land.

First, Mars does not have a magnetosphere. This helps fend off the worst of the cosmic radiation here on Earth. What does he propose to replace it? The article is light on the details. Second, isn't the understanding still that Mars has insufficient gravity to preserve its atmosphere and so the solar wind strips the atoms and molecules right off the top, thus explaining the low pressure we see today? How do you counter that?

If I had mod points I'd give you one.
If my memory is correct, Earth's spinning liquid metal core is what gives us our magnetosphere, and protects our upper atmosphere from getting "sandblasted" away by the solar wind. Mars doesn't have a magnetoshpere, which is the reason why some astronomers think its core has cooled and is solid. Without that magnetosphere, the solar wind will just blast whatever atmosphere we put on it away.

Which brings us to the question of why we're looking at Mars at all, and instead we don't turn our cameras to Venus.

Venus is nearly the same mass as Earth so it has roughly the same gravity. The surface is a lot hotter and the atmosphere is a lot denser, but it seems to me it'd be much more feasible to scrub an atmosphere than invent a new one, all someone needs to do is come up with a solution (or multitude of solutions) for turning the bulk CO2 of the Venusian atmosphere into something else (perhaps hydrocarbons, carbon nanotubes, hell it could be graphite or diamonds for whatever reason).

Venus doesn't have a magnetosphere either, but it at least maintains its atmosphere and perhaps if it were left at least more dense than our atmosphere it would protect people from the radiation of space (or perhaps with the same machines we invent to do CO2 scrubbing we can make an Ozone layer too?)

Hell, if we were so bold as to do it, we could ship the gasses off Venus and onto Mars and inhabit both. Venus should still have plenty of atmosphere after we've bled off the excess junk within it to remain habitable. (I guess the only real question left is water, which we'd have to convert from whatever trace we could pull out of the atmosphere).

You are thinking way to small. We need to move Mars and Venus to the trailing Lagrange points in Earth's orbit. That will put them both in the water zone. Then, send a stream of comets from the Oort cloud to crash into Mars - just need to be careful not to miss. Venus just gets the good old fashioned algae/plants method of atmospheric reduction.

By the time we use up Earth, Mars will be ready for wholesale migration, and by the time Mars is used up, Venus will be done simmering. By that time we will be assembling new planets from scratch with asteroids, Mercury, Pluto, Sedna, and whatever other junk we can find.

Second, isn't the understanding still that Mars has insufficient gravity to preserve its atmosphere and so the solar wind strips the atoms and molecules right off the top, thus explaining the low pressure we see today? How do you counter that?

As a bonus, we can just use the huge underground alien terraforming equipment that is already installed!!Whilst terraforming a nearby planet seems interesting, I would like to see more investment of both research and cash into either orbital habitats or preferably mobile space habitats. The idea of living on a large space station seems to me to be more interesting than settling a different planet... Oh whilst Im on the subject,- a FTL drive, I'd like one of those, plus a teleportation device, oh and a repl

We don't even know 100% for certain (political and environ-assertions aside) if we're capable of modifying temperatures on Earth by a couple of degrees over 200+ years of industrialization... and this guy suggests that we can jack up an atmosphere 100x thinner, w/ 100x the CO2, by at least 100+ degrees Fahrenheit, in less than 100 years?

We're not even counting the gravity well penalties of getting back and forth that'll be present, at least within the next 100 years.

I hate to be the Luddite in the room, but given our track record on this planet, I'm not really sure I want us to be inflicting our particular brand of 'progress' on another world. At least not until we know a little bit more about what we'd be losing in terms of the current Martian environment (such as it is). Until then, maybe we should just stick to the planet we're already monkeying around with.

Why Mars? Why not Antarctic glaciers, Gobi desert, Kazakh wastelands, Belarus swamps and Alaskan tundra? Hey, the good old Earth has places that model the conditions of pretty much every planet you can imagine [hazardous included], except perhaps gas giants. Now, where do I go to have the illusion of being on the ancient Foth of Avalars...

The Mars Society [marssociety.org] - To further the goal of the exploration and settlement of the Red Planet.

The Moon Society [moonsociety.org] - An international nonprofit educational and scientific foundation formed to further the creation of communities on the Moon involving large-scale industrialization and private enterprise.

Space Studies Institute [ssi.org] - `SSI's stated mission is: Opening the energy and material resources of space for human benefit by completing the missing technological links to make possible the productive use of the abundant resources in space.`

International Space University [isunet.edu] - `The International Space University provides graduate-level training to the future leaders of the emerging global space community at its Central Campus in Strasbourg, France, and at locations around the world. ` (mentions 'systems engineering' on the About page)

Space Settlement Institute [space-sett...titute.org] - `The Space Settlement Institute is a non-profit association founded to help promote the human colonization and settlement of outer space. `

Cygo's Space Initiative [cygo.com] - plan and conduct exploration missions to minor planets, build and mass produce (while in space) a multi-purpose interconnectable module, and to offer products and services using space and the materials therefrom.

Freeluna [freeluna.com] - `Freeluna.com is dedicated to the proposition that the colonization of outer space is critical for the long term survival of the human species, and that colonization of the moon and the exploitation of the moon's natural resources is one of the very best first steps in that incredible journey off planet.`... and when I first visited this page, I was visitor #3371. Yikes. Contact: Bill Clawson, wclawson@freeluna.com

Island One Society [islandone.org] - associated with the Artemis society, seems to be mostly a resource-help site.

The Living Universe Foundation [luf.org] - `The Living Universe Foundation seeks to bring the galaxy alive with life from Earth, while healing the damage that humanity has already inflicted upon the Earth. We believe that expansion into space in the immediate future is a step towards accomplishing this aim.` turmith@yahoo.com --- This organization was inspired by the publication of a certain book. This is heavily related to Project Atlantis or Oceania [oceania.org] (artifical floatin

1. a century? maybe 500-1,000 years, even with a massive economic and political commitment and AFTER the miraculous technological breakthroughs

2. why does venus get such short thrift? i'm thinking along the lines of energy investment and simple entropy: in my mind, to precipitate matter out of an atmosphere, and to dissipate heat, seems to be an easier task than accumulating atmospheric mass and stoking atmospheric heat. yes, even with runaway, geometric catalyst-driven processes, i think it is easier to destroy than it is to create. of course, to do this to venus will be excedingly difficult. but why do you think mars would be easier?

Terraforming Mars is neither necessary nor desirable. Within perhaps 50 years we could easily have human-level AI and advanced robotics. Such robots could be designed for the Martian environment as it exists now. It will prove much easier to adapt our descendants -- our mind children -- to Mars (and many other environments that are hostile to humans) than it would ever be to adapt Mars to us.

In fact, the more optimistic transhumanists would tend to assume that people alive today may see a time when they can upload or upgrade into an advanced robotic form themselves -- so it wouldn't even necessarily be our remote sort-of-descendants who colonize Mars, it could be us, suitably transformed.

Conventional wisdom is that Mars will be explored by robots, then colonized by humans. I turn that idea on it's head. Humans will explore Mars -- today's robotic probes are too crude and limited, so that a single manned expedition could do scientific work that would take decades, maybe centuries, with robots. The other side of that coin is that 50-100 years from now humans will become obsolete for space travel and colonization. The people who actually live on Mars and build a society there will be synthetic people, not homo sapiens.

A physicist talking about chemistry and biology, and a retiree talking about how easy/cheap/fast/simple it would be for you young people to do, if you only had the kind of vision we had back in the day.

I'm all for eventually terraforming Mars once we've determined that there's no existing life there, but to do so before then would be a scientific loss on an unimaginable scale.

Given that we're still discovering new species (microscopic ones by the gazillion, and still finding occasional large ones too) on earth, despite a huge exploratory effort that's been underway for hundreds of years, I think it's a bit early (massive understament) to think we've determined that mars is lacking any life at all

What's that old line? Something like "why are we all into terraforming other worlds while we're busy venusforming earth?"

I love the idea of massive engineering projects making useful changes, but also understand that there is going to be a HUGE heap of the law of unintended consequences because these systems are so difficult to model accurately.

With Mars weak magnetosphere, it would be a constant battle to generate the gases needed to sustain life VS. Solar wind that strips those gases of the planet and into space.

The magnetosphere is the magnetic field generated by the planet. It essentially creates a shield around the planet that protects it from various kinds of solar radiation and the ill effects caused by said radiation.

Mars is, on a planetary scale,.... dead. There is no longer a mechanism within the planet itself to generate the magnetic field needed to protect the atmosphere (even if we could create one).

Mars does not have enough mass to hold an Earth-like atmosphere (Nitrogen and Oxygen mostly) that has enough energy (warm enough) with enough pressure to sustain Earth-like life.

If we took the atmosphere as it is on this planet and actually brought it to Mars, it would have been gone from that planet in the matter of weeks, most of free N and O2 at the molecule speeds that we see on Earth would just jump out of the Mars gravitaty well, and it would happen extremely fast.

I believe the real problem isn't the climate, or the high carbon dioxide atmosphere; the real problem is that Mars's atmosphere is very low density. The air pressure in Mars (less than 1% of that on Earth according to Wikipedia) won't be sufficient for us earthlings to breathe comfortably if at all.

I'm sure that something will develop that we just can't see yet. We've never terraformed a planet before so we're just going off on computer models which are never 100% accurate.

Just say that we send a rocket ship that spews spores or whatever photosynthetic organism. There is a 70% survival rate, they get situated, some martian monsoon rips up a path and sends it up in the upper atmosphere where it rides the current for half a year where it mixes with some native vegetation and grows gangbusters. Density increases within 40 years - not part of the original model.

Mars will never be habitable for us earthlings to live comfortably. Our bone density would suffer too with a year long round trip and 6 month minimum stay, that's 18 months away from Earth's gravity. Not too good for our health but we're smart enough to figure out a solution.

There is likely enough gases trapped internally to Mars to create the atmosphere we would need. Mars no longer has plate techtonic movement like Earth, which on Earth gets the gases we need back out to the atmosphere. To get some action, probably not full plate techtonics, but at least enough to release those gases we already have an example of what is needed by the way the Earth gets its gases, via stress from the moon. We need to farm comets and other mass to impact with Mars moon until we increase its ma

Here's a "kids" page, that addresses the magnetic field [nasa.gov] of Mars (and Venus). As Venus also has very little magnetic field, perhaps I'm wrong about that whole stripping thing. This site [ucla.edu] seems to be saying that it's a combination of Mars' low gravity and weak magnetic field. Keep in mind that Titan (with its weak gravity) also has an atmosphere. OTOH, Mercury with a very strong magnetic field does not have an atmosphere. Just some rambling thoughts.

anaerobic bacteria, the kinds of things that are used to living in very hostile environments.

I'm more curious about where they expect to get the water. Sure, there may be a lot of it around, but the vapor pressure is going to be so low it would be very hard for bacteria to keep their water inside and not just instantly dry up.

Pity that Saturn's rings turned out to be dust instead of ice bergs. I keep thinking about that old Isaac Asimov story...

What are you talking about? Saturn's rings are a mix of dust and ice. They're more ice-enriched toward the outside and more dust/rock enriched toward the inside. The E-ring, for example, is almost pure ice, largely spewed forth from Enceladus.

I'm more curious about where they expect to get the water.

That is the rub, isn't it? No matter what, any terraforming organisms or other self-replicators are going to have to be very heavily engine

Simply producing gases from the existing atmosphere would be helpful in and of itself, and a difficult process for bacteria to reverse.

The "existing atmosphere" hardly exists, and that's the problem. You *have* to get gasses from some sort of solids if you want to have an atmosphere on Mars. Since there's only a small amount of CO2 trapped in dry ice, this means that having your replicators (biological or otherwise) turn oxidized metals into unoxidized metals via solar energy. The problem with that is th

Are you guys kidding me? You talk about terraforming as if it's just another trick we have in our arsenal, which it isn't. But, the technology aside, there are other issues that will trump that. For example, what about the militant lobby of folks who will undoubtedly make this into 'the evil humans rushing out to screw up another planet after they can't even keep a grip on their own?' You think Eco Terrorism is bad now, wait until someone starts moralizing on the idea of just commandeering a whole planet for experimental purposes. I personally think that it's as good of a laboratory as any, but I really think this would make the alarmist triply so. Think about it, what about property rights, mineral rights, and political philosophy, the interaction of religious idiots, and the mass media distortion... It's all just a huge cluster fsck waiting to happen, which is why I think it will never happen. I'd hope it does, but I don't see anything able to surmount those socio-political issues any time in the next couple of centuries, let alone the next 93 years.

Only when the political will to do so is required, say population explosion
is causing massive food/energy shortages will something like this possibly
be considered.

It costs huge amounts of money to send every kilogram to orbit let alone Mars. If they do get Mars to a colonizable state anytime soon they won't be sending millions of Average Joe's to live there anytime soon.

The question is why should we mess up Mars, we're just barely starting on the road to fix the damage we've done to our own planet.

Yes, I'd hate to ruin all that prinstine forest over there on the red planet.
I couldn't care less about "ruining" currently lifeless worlds. Even if we found something similar to bacteria I wouldn't care if we went in there and "ruined" it by putting life on the same planet.
Only worlds like Europa where there's a least the potential for some multi-cellular life as we know it would I proceed with caution.
Life is special and we should put it everywhere we can. While potentially we might be messing with some Martian nano-scale bacteria and the like, the risks are far outweighed by the gains.

Oh, and as far as "ruining" Earth goes. We are a product of the Earth. Humans are natural. We're life and evolved from the same process that gave us sharks and walnuts and horses. We're probably Earth's most precious resource because we're the lone form of life that can get to other planets, that can spread out beyond Earth. The Earth is far from ruined, it still supports trillons and trillons of individual life forms. And one form of life, us, is just getting capable of one of the greatest achievements possible. Spreading life out beyond the planet it formed on.

Actually, although terraforming is not really feasable, venus is actually a very attractive place to build a colony. Although the surface of the planet is quite inhospitable, at cloud top level conditions are extremely well suited for earth life. In addition, breathable air is a lifting gas, so your colony naturally floats on the cloudtops and solar energy is very abundant.http://powerweb.grc.nasa.gov/pvsee/publications/ve nus/VenusColony_STAIF03.pdf [nasa.gov]